Accelerator for vulcanization purposes



Patented Aug. 23, 1932 UNIT STATES PATENT OFFICE WILHELM LOMMEL, OFWIESDORF-ON-THE-RHINE, THEODOR GOOST', OF LEVERKUSEN- ON-THE-RHINE, ANDHERMANN FRIEDRICH, 0F WIESDORF-ON-THE-RHINE, GER- MANY, ASSIGNORS TO I.G. FARBENINDUSTRIE AKTIENGESELLSCHAFT, OF FRANK- FOR-T-ON-TI-IE-MAIN,GERMANY ACCELERATOR FOR VULCANIZATION PURPOSES No Drawing. Applicationfiled September 5, 1930, Serial No. 480,020, and in Germany November 8,1927.

The present invention relates to a process of vulcanizing rubbercompounds and consists in efi'ecting the vulcanization in the presenceof a salt of a dithioca-rbamic acid of the probable formula:

wherein R means the cyclohexyl group or a hrnnologue thereof, R standsfor a hydrocarbon radical which may be linked up with R to form a ringconfiguration. The invention furthermore relates to the vulcanizedrubber compounds obtainable by the process above identified.

In accordance with the invention a compound of the above formula isincorporated, for example, by rolling or kneading within the rubbercompounds to be vulcanized together with or apart from the otheringredients usually employed in vulcanization processes, such as sulfur,selenium, aromatic nitro co1npounds+1netal oxides or other vulcanizingagents, fillers, plasticizing agents, pigments, etc. vulcanization ofthe mixtures th'us produced is performed by heating with or without theapplication of superatmospheric pressure, advantageously to temperaturesbetween about 100-150 C.

It may be mentioned that the term rubber compound is intended to includenatural rubber varieties and artificial rubber like masses obtainable bypolymerizing a rubber forming hydrocarbon, such as buta-diene (1.3) orhomologues or analogues thereof alone or in admixture with othersuitable compounds capable of being polymerized, such as styrol,vinylnaphthalenes, etc. Obviously, instead of a single one' of ourvulcanization accelerators, mixtures of two or more of the same may beemployed and, if desired, accelerators of another type may be usedsimultaneously. The preparation of our vulcanization accelerators may beperformed, for example, according to the methods described in the GermanPatents 459,628, 497,241 or 498,280. As salts of dithiocarbamic acidsthere may be mentioned those with primary,.seoondary or Emample 1 100parts of smoked sheets 10 parts of zinc white 2.5 parts of sulfur 0.5part of the ethylcyclohexylamine salt of ethylcyelohexyldithiocarbamicacid of the formula oHn CaHn N-C-SILH-N are mixed by rolling or kneadingand the mixture is vulcanized at 130 C. for 20 minutes. A vulcanizate isthus obtained showing a tensile strength of about 160 kg/sqcm at astretch of about 690%.

E wample 2 100 parts of smokedsheets 10 parts of zinc white 6 parts ofsulfur 1 part of the ethyl-hexahydro-para-toluidine salt ofethyl-hexahydro-paratolyl-dithiocarbamio acid of the forare mixed byrolling or kneading and the mixture is vulcanized at 120 C. for 30minutes. A vulcanizate is thus obtained showing a tensile strength ofabout 166 kg/sqcm at a stretch of about 680%.

Ewample 3 100 parts of smoked sheetsv 10 parts of zinc white 2 parts ofsulfur 1 part of the cyclohexylamine salt ofethylcyclohexyl-dithiocarbamic acid of the formula:

are mixed by rolling or kneading and the mixture is vulcanized at 105 C.for 30 minutes. A vulcanizate is thus obtained showing a tensilestrength of about 192 kg/sqcm.

Example 4 100 parts of smoked sheets 5 parts of zinc White 2.5 parts ofsulfur 0.6 part of the dekahydroquinaldine salt ofethylcyclohexyl-dithiocarbamic acid of the formula;

Hz III:

CaHn

are mixed by rolling or kneading and the mixture is vulcanized atabout105 C. for 20 minutes. A vulcanizate is thus obtained showing a tensilestrength of 183 kg/sqcm at a stretch of about 806%.

Example 5 100 parts of a butadiene-sodium polymerizate 60 parts ofcarbon black 25 parts of zinc white 2 parts of stearic acid 2 parts oftar 2 parts of colophony 1 part of sulfur 1 part of thedekahydroquinaldine salt of dekahydroquinaldine dithiocarbamic acid ofthe formula H2 H2 H2 H2 H H W Ha Hf H2 H CH3 I H H CH3 H H i a CSH.H

are mixed by rolling or kneading and the mixture is vulcanized at about140 C. for 40 minutes. A Vulcanizate is thus obtained showing a tensilestrength of 183 kg/sqcm at a stretch of about 740%. r

E wample 6 OM O are mixed by rolling or kneading and the mixture isvulcanized at about 140 C. for 40 minutes. A vulcanizate is thusobtained showing a tensile strength of 160 kg/sqcm at a stretch of 650%.

Example 7 100 parts of smoked sheets 5 parts of zinc oxide 2.5 parts ofsulfur 0.5 part of the ethylcyclohexylamine salt ofcyclohexylethyl-dithiocarbamic acid of the formula:

are mixed by rolling or kneading and the mixture is vulcanized at about105 C. for 30 minutes. A vulcanizate is thus obtained showing a tensilestrength of about 252 kg/sqcm at a stretch of 785%.

Example 8 100 parts of smoked sheets 1 part of paraffin oil 1.5 parts ofstearic acid 3 parts of activated zinc oxide 2.5 parts of surfur 05 partof the zinc salt of dekahydroquinaldine-dithiocarbamic acid of theformula:

are mixed by rolling or kneading and the mixture is vulcanized atabout105 C. for 50 minutes. A vulcanizate is thus obtained showing a tensilestrength of .about 198 kg/sqcm.

erssae Similar results will be obtained by replacing the acceleratorsemployed 1n the above examples, for example by:

11; H; i H: I H2 H: H: a H1 It may be mentioned that a great part of theaccelerators used in the present application may also be employed bydissolving them in a suitable organic solvent, such as benzene or thelike, dipping the rubber compound to be vulcanized into the solution andheating it to a suitable temperature after having removed it from thesolution.

1. Process for the manufacture of vulcanized rubber compounds whichconsists in effecting the vulcanization in the presence of a salt of acompound of the probable formula:

wherein R stands for the cyclohexyl group or a homologue thereof and Rstands for a hydrocarbon radical which may be linked up with R to form aring configuration.

2. Process for the manufacture of vulcanized rubber compounds whichconsists in effecting the vulcanization in the presence of a salt of acompound of the prob-able formula:

wherein R stands for the cyclohexyl group or a homologue thereof and Rstands for an alkyl group which may be linked up with R to form a ringconfiguration.

3. Process for the manufacture of vulcanized rubber compounds whichconsists in effecting the vulcanization in the presence of a compound ofthe probable formula:

wherein R means a cyclohexyl group or a homologue" thereof, R means ahydrocarbon radical which may be linked up with R to form a ringconfiguration.

4. Process for the manufacture of vulcanized rubber compounds whichconsists in effecting the vulcanization in the presence of a compound ofthe probable formula:

wherein R means a cyclohexyl group or a homologue thereof, R means analkyl group which may be linked up with R to form a ring configuration.

5. Process for the manufacture of vulcanized rubber compounds whichconsists in effecting the vulcanization in the presence of a compound ofthe probable formula:

6. Process for the manufacture of vulcanized rubber compounds WhlChconslsts in effecting the vulcanization in the presence of a compound ofthe probable formula:

7. As new products of manufacture vulcantures.

WILHELM LOMMEL. THEODOR GOOST.

1o HERMANN FRIEDRICH.

Certificate of Correction Patent No. 1,873,936. August 23, 1932.

WILHELM LOMLIEL ET AL. I nuggsriigrglgelclirtiafilegrgmt errortappearsfiifi the pfintdsgecificgion of the abovecorrec 1on as o oWs: ae t Out he formula and usert instea g mes o mcluslve OE H H2 11 H HN-o-sH.rr- H, e, 5

V O a H 2 same page, lines 119.170 125, strike out the forn ula andinsert instead 4 I H2 H: i H2 H:

H H H H H N-O-SZnSC-l H:

H E 2 H: OHsH H2 page 3, lines '27 to 34, strike out the right-handportion of the formula and insert instead- -SH.H

C 3 Hz and that the said Letters Patent should be read with thesecorrections there'mthat the same may conform to the record of the casein the Patent Office.

Signed and sealed this 14th day of February, A. D. 1933. 4

[emu] M. J. MOORE,

Acting Oommissz'omr of Patents.

